Tagged: Messier 87 Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 1:12 pm on April 13, 2019 Permalink | Reply
    Tags: "When a Black Hole Finally Reveals Itself, , It Helps to Have Our Very Own Cosmic Reporter", Messier 87,   

    From The New York Times: “When a Black Hole Finally Reveals Itself, It Helps to Have Our Very Own Cosmic Reporter” 

    New York Times

    From The New York Times

    April 12, 2019
    Aidan Gardiner

    Astronomers announced Wednesday that they had captured the first image of a black hole. The Times’s Dennis Overbye answers readers’ questions.

    2
    The first image of a black hole, from the galaxy Messier 87.Credit Event Horizon Telescope Collaboration, via National Science Foundation

    1
    Dennis Overbye, cosmic reporter for The New York Times, answering readers’ questions at his desk.Credit Aidan Gardiner/The New York Times

    When radio waves from the depths of a nearby galaxy known as Messier 87 traveled some 55 million light-years to a constellation of telescopes on Earth, revealing to humanity the face of a black hole for the first time, people around the planet paused in wonder.

    Why does it look like a doughnut? How scary is it when two of these things smash into each other? And if light can’t escape a black hole, what are we even looking at?

    Our coverage Wednesday of the first ever image of a black hole, by our cosmic reporter Dennis Overbye, drew a huge response from our readers. Dennis graduated from M.I.T. with a physics degree and was a Pulitzer Prize finalist in 2014 for his coverage for The New York Times of the race to find the Higgs boson. He sat down Thursday with his feet on his desk, beside a photo of the black hole, to answer some of our readers’ questions and respond to their feedback.

    Below are some of the exchanges that he had during an AMA on Reddit and in the comments on his article. They are edited for clarity.

    What does this image really tell us besides black holes are round?

    This is the first look into the central engine that generates the enormous energies put out by quasars, radio galaxies and other so-called active galactic nuclei. The action all starts down at the edge of oblivion, in a maelstrom of hot gas, gravity, magnetic fields and otherworldly pressures. It extends out beyond the far reaches of the galaxy, as jets of radio-wave energy moving at nearly the speed of light; these lobes of radio energy can accompany shock waves capable of blowing the gas out of galaxies or even entire clusters of them, preventing stars from forming. Through these mechanisms, black holes, blowing hot and cold, control the growth and structure of galaxies. It all starts in the accretion disk, the doughnut of doom.

    Why does it look like a “doughnut of doom” and not a sphere?

    When matter falls together into a black hole, or in almost any other situation, it has angular momentum, and takes on the shape of a flattened pancake spinning around the central attraction. Also, the black hole is probably spinning, pulling the disk around in the same direction. We are seeing the disk almost directly face-on, so it looks like a doughnut hole. (From edge-on it would look different.) Bent by gravity, light wraps around the hole on its way to our eyes, so the black hole magnifies and distorts the image of the accretion disk.

    Will we ever get a clearer image of this black hole?

    We will. The key is to observe black holes at shorter and shorter radio wavelengths, which allows more and more detail to be resolved. The latest images were recorded at a wavelength of 1.3 millimeters in the microwave band. The Event Horizon team hopes to go to shorter wavelengths in the future, and to use more antennas, including one in space, which would increase the size of their “virtual telescope” and also increase resolution.

    Do you feel that coverage of the breakthrough minimized the role of Katherine Bouman, a researcher at the Harvard-Smithsonian Center for Astrophysics?

    The issue of the unsung hero or heroine is a big problem, especially in Big Science, which the Event Horizon Telescope is surely part of.

    There were 207 people in the collaboration, according to one of the physicists I talked to that day. I am sure that many crucial contributions and rich anecdotes of behind-the-scenes science got missed.

    In time, these will come out in more thoughtful, longer narratives. On the day of the announcement there was a tsunami of information released at 9 a.m., and a rush to post stories as soon as possible, an unfortunate fact of the internet age.

    What does current science tell us is supposed to happen in the gravitational extremes of a black hole?

    That’s the biggie everybody wants to know. Whatever happens there, it probably is similar to what happened, maybe in reverse, in the Big Bang. Space, time, matter all go away, replaced by what? Some people think the answers might come from string theory, which unites gravity with quantum theory. But for now it remains an untestable, but mathematically elegant, speculation.

    What happens when two black holes collide?

    Such collisions have happened and been recorded by the LIGO gravitational wave observatory.


    They vibrated the space-time continuum like a drum and released as much energy in a fraction of a second as all the stars in the observable universe. The result in each case was an even bigger, blended black hole.

    But outside the event horizon, the gravitational field of a black hole is just like that of a star and it is no more dangerous. Black holes don’t go roaming around looking to swallow you. They only hurt if you touch them, in which case you won’t ever be able to let go. Otherwise they are like any other animal that you would just let go, and mind your own business.

    How is any of this relevant to our day-to-day lives?

    It can certainly provide context to your daily life, but it won’t move the markets. It will, or could, move your soul. However, Einstein, when he invented the sort of trampoline universe described by general relativity, did not dream that it would lead to pocket devices that keep time and tell you precisely where you are on Earth — that is to say, GPS. But they depend crucially on general relativity to tell you where you are. So who knows?

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 6:10 pm on April 11, 2019 Permalink | Reply
    Tags: , , , , , Messier 87, , , , ,   

    From Nautilus: “First Black-Hole Image: It’s Not Looks That Count” 

    Nautilus

    From Nautilus

    Apr 11, 2019
    Sabine Hossenfelder

    1
    FIRST LOOK: The Event Horizon Telescope measures wavelength in the millimeter regime, too long to be seen by eye, but ideally suited to the task of imaging a black hole: The gas surrounding the black hole is almost transparent at this wavelength and the light travels to Earth almost undisturbed. Since we cannot see light of such wavelength by eye, the released telescope image shows the observed signal shifted into the visible range.Event Horizon Telescope Collaboration.

    “The Day Feynman Worked Out Black-Hole Radiation on My Blackboard”
    2
    After a few minutes, Richard Feynman had worked out the process of spontaneous emission, which is what Stephen Hawking became famous for a year later.Wikicommons.

    The Italian 14th-century painter, Giotto di Bondone, when asked by the Pope to prove his talent, is said to have swung his arm and drawn a perfect circle. But geometric perfection is limited by the medium. Inspect a canvas closely enough, and every circle will eventually appear grainy. If perfection is what you seek, don’t look at man-made art, look at the sky. More precisely, look at a black hole.

    Looking at a black hole is what the Event Horizon Telescope has done for the past 12 years. Yesterday, the collaboration released the long-awaited results from its first full run in April 2017. Contrary to expectation, their inaugural image is not, as many expected, Sagittarius A*, the black hole at the center of the Milky Way. Instead, it is the supermassive black hole in the elliptic galaxy Messier 87, about 55 million light-years from here. This black hole weighs in at 6.5 billion times the mass of our sun, and is considerably larger than the black hole in our own galaxy [1,000 times the size of SGR A*]. So, even though the Messier 87 black hole is a thousand times farther away than Sagittarius A*, it still appears half the size in the sky.

    The Event Horizon Telescope (EHT) is not less remarkable than the objects it observes. With a collaboration of 200 people, the EHT uses not a single telescope, but a global network of nine telescopes. Its sites, from Greenland to the South Pole and from Hawaii to the French Alps, act in concert as one. Together, the collaboration commands a telescope the size of planet Earth, staring at a tiny patch in the northern sky that contains the Messier-87 black hole.

    Event Horizon Telescope Array

    Arizona Radio Observatory
    Arizona Radio Observatory/Submillimeter-wave Astronomy (ARO/SMT)

    ESO/APEX
    Atacama Pathfinder EXperiment

    CARMA Array no longer in service
    Combined Array for Research in Millimeter-wave Astronomy (CARMA)

    Atacama Submillimeter Telescope Experiment (ASTE)
    Atacama Submillimeter Telescope Experiment (ASTE)

    Caltech Submillimeter Observatory
    Caltech Submillimeter Observatory (CSO)

    IRAM 30m Radio telescope, on Pico Veleta in the Spanish Sierra Nevada,, Altitude 2,850 m (9,350 ft)


    Institut de Radioastronomie Millimetrique (IRAM) 30m

    James Clerk Maxwell Telescope interior, Mauna Kea, Hawaii, USA
    James Clerk Maxwell Telescope interior, Mauna Kea, Hawaii, USA

    Large Millimeter Telescope Alfonso Serrano
    Large Millimeter Telescope Alfonso Serrano

    CfA Submillimeter Array Mauna Kea, Hawaii, USA, Altitude 4,080 m (13,390 ft)

    Submillimeter Array Hawaii SAO

    ESO/NRAO/NAOJ ALMA Array
    ESO/NRAO/NAOJ ALMA Array, Chile [recently added]

    South Pole Telescope SPTPOL
    South Pole Telescope SPTPOL [recently added]

    Future Array/Telescopes

    NOEMA (NOrthern Extended Millimeter Array) will double the number of its 15 meter antennas of its predecessor from six to twelve, located in the French Alpes on the wide and isolated Plateau de Bure at an elevation of 2550 meters

    NSF CfA Greenland telescope


    Greenland Telescope

    ARO 12m Radio Telescope, Kitt Peak National Observatory, Arizona, USA, Altitude 1,914 m (6,280 ft)


    ARO 12m Radio Telescope

    In theory, black holes are regions of space where the gravitational pull is so large that everything, including light, becomes trapped for eternity. The surface of the trapping region is called the “event horizon.” It has no substance; it is a property of space itself. In the simplest case, the event horizon is a sphere—a perfect sphere, made of nothing.

    In reality, it’s complicated. Astrophysicists have had evidence for the existence of black holes since the 1990s, but so far all observations have been indirect—inferred from the motion of visible stars and gas, leaving doubt as to whether the dark object really possesses the defining event horizon. It turned out difficult to actually see a black hole. Trouble is, they’re black. They trap light. And while Stephen Hawking proved that black holes must emit radiation due to quantum effects, this quantum glow is far too feeble to observe.

    But much like the prisoners in Plato’s cave, we can see black holes by observing the shadows they cast. Black holes attract gas from their environment. This gas collects in a spinning disk, and heats up as it spirals into the event horizon, pushing around electric charges. This gives rise to strong magnetic fields that can create a “jet,” a narrow, directed stream of particles leaving the black hole at almost the speed of light. But whatever strays too close to the event horizon falls in and vanishes without a trace.

    At the same time black holes bend rays of light, bend them so strongly, indeed, that looking at the front of a black hole, we can see part of the disk behind it. The light that just about manages to escape reveals what happens nearby the horizon. It is an asymmetric image that the astrophysicists expect, brighter on the side of the black hole where the material surrounding it moves toward us, and darker where it moves away from us. The hot gas combined with the gravitational lensing creates the unique observable signature that the EHT looks out for.

    The experimental challenge is formidable. The network’s telescopes must synchronize their data-taking using atomic clocks. Weather conditions must be favorable at all locations simultaneously. Once recorded, the amount of data is so staggeringly large, it must be shipped on hard disks to central locations for processing.

    The theoretical challenges are not any lesser. Black holes bend light so much that it can wrap around the horizon multiple times. The resulting image is too complicated to capture in simple equations. Though the math had been known since the 1920s, it wasn’t until 1978 that physicists got a first glimpse of what a black hole would actually look like. In that year, the French astrophysicist Jean-Pierre Luminet programmed the calculation on an IBM 7040 using punchcards. He drew the image by hand.

    Today, astrophysicists use computers many times more powerful to predict the accretion of gas onto the black hole and how the light bends before reaching us. Still, the partly turbulent motion of the gas, the electric and magnetic fields created by it, and the intricacies of the particle’s interactions are not fully understood.

    The EHT’s observations agree with expectation. But this result is more than just another triumph of Einstein’s theory of general relativity. It is also a triumph of the astronomers’ resourcefulness. They joined hands and brains to achieve what they could not have done separately. And while their measurement settles a long-standing question—yes, black holes really do have event horizons!—it is also the start of further exploration. Physicists hope that the observations will help them understand better the extreme conditions in the accretion disk, the role of magnetic fields in jet formation, and the way supermassive black holes affect galaxy formation.

    When the Pope received Giotto’s circle, it was not the image itself that impressed him. It was the courtier’s report that the artist produced it without the aid of a compass. This first image of a black hole, too, is remarkable not so much for its appearance, but for its origin. A black sphere, spanning 40 billion kilometers, drawn on a background of hot gas by the greatest artist of all: Nature herself.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Welcome to Nautilus. We are delighted you joined us. We are here to tell you about science and its endless connections to our lives. Each month we choose a single topic. And each Thursday we publish a new chapter on that topic online. Each issue combines the sciences, culture and philosophy into a single story told by the world’s leading thinkers and writers. We follow the story wherever it leads us. Read our essays, investigative reports, and blogs. Fiction, too. Take in our games, videos, and graphic stories. Stop in for a minute, or an hour. Nautilus lets science spill over its usual borders. We are science, connected.

     
  • richardmitnick 10:08 am on April 10, 2019 Permalink | Reply
    Tags: , Although the telescopes are not physically connected they are able to synchronize their recorded data with atomic clocks — hydrogen masers — which precisely time their observations., , , , BlackHoleCam, , Data were flown to highly specialised supercomputers — known as correlators — at the Max Planck Institute for Radio Astronomy and MIT Haystack Observatory to be combined., , , Messier 87, Sagittarius A* the supermassive black hole at the center of our galaxy, VLBI-very-long-baseline interferometry   

    From European Southern Observatory: “Astronomers Capture First Image of a Black Hole” 

    ESO 50 Large

    From European Southern Observatory

    10 April 2019

    Heino Falcke
    Chair of the EHT Science Council, Radboud University
    The Netherlands
    Tel: +31 24 3652020
    Email: h.falcke@astro.ru.nl

    Luciano Rezzolla
    EHT Board Member, Goethe Universität
    Germany
    Tel: +49 69 79847871
    Email: rezzolla@itp.uni-frankfurt.de

    Eduardo Ros
    EHT Board Secretary, Max-Planck-Institut für Radioastronomie
    Germany
    Tel: +49 22 8525125
    Email: ros@mpifr.de

    Calum Turner
    ESO Public Information Officer
    Garching bei München, Germany
    Tel: +49 89 3200 6655
    Email: pio@eso.org

    ESO, ALMA, and APEX contribute to paradigm-shifting observations of the gargantuan black hole at the heart of the galaxy Messier 87.

    1
    The Event Horizon Telescope (EHT) — a planet-scale array of eight ground-based radio telescopes forged through international collaboration — was designed to capture images of a black hole. Today, in coordinated press conferences across the globe, EHT researchers reveal that they have succeeded, unveiling the first direct visual evidence of a supermassive black hole and its shadow.

    This breakthrough was announced today in a series of six papers published in a special issue of The Astrophysical Journal Letters. The image reveals the black hole at the centre of Messier 87 [1], a massive galaxy in the nearby Virgo galaxy cluster. This black hole resides 55 million light-years from Earth and has a mass 6.5 billion times that of the Sun [2].

    The EHT links telescopes around the globe to form an unprecedented Earth-sized virtual telescope [3]. The EHT offers scientists a new way to study the most extreme objects in the Universe predicted by Einstein’s general relativity during the centenary year of the historic experiment that first confirmed the theory [4].

    “We have taken the first picture of a black hole,” said EHT project director Sheperd S. Doeleman of the Center for Astrophysics | Harvard & Smithsonian. “This is an extraordinary scientific feat accomplished by a team of more than 200 researchers.”

    Black holes are extraordinary cosmic objects with enormous masses but extremely compact sizes. The presence of these objects affects their environment in extreme ways, warping spacetime and superheating any surrounding material.

    “If immersed in a bright region, like a disc of glowing gas, we expect a black hole to create a dark region similar to a shadow — something predicted by Einstein’s general relativity that we’ve never seen before,” explained chair of the EHT Science Council Heino Falcke of Radboud University, the Netherlands. “This shadow, caused by the gravitational bending and capture of light by the event horizon, reveals a lot about the nature of these fascinating objects and has allowed us to measure the enormous mass of Messier 87’s black hole.”

    Multiple calibration and imaging methods have revealed a ring-like structure with a dark central region — the black hole’s shadow — that persisted over multiple independent EHT observations.

    “Once we were sure we had imaged the shadow, we could compare our observations to extensive computer models that include the physics of warped space, superheated matter and strong magnetic fields. Many of the features of the observed image match our theoretical understanding surprisingly well,” remarks Paul T.P. Ho, EHT Board member and Director of the East Asian Observatory [5]. “This makes us confident about the interpretation of our observations, including our estimation of the black hole’s mass.”

    “The confrontation of theory with observations is always a dramatic moment for a theorist. It was a relief and a source of pride to realise that the observations matched our predictions so well,” elaborated EHT Board member Luciano Rezzolla of Goethe Universität, Germany.

    Creating the EHT was a formidable challenge which required upgrading and connecting a worldwide network of eight pre-existing telescopes deployed at a variety of challenging high-altitude sites. These locations included volcanoes in Hawai`i and Mexico, mountains in Arizona and the Spanish Sierra Nevada, the Chilean Atacama Desert, and Antarctica.

    The EHT observations use a technique called very-long-baseline interferometry (VLBI) which synchronises telescope facilities around the world and exploits the rotation of our planet to form one huge, Earth-size telescope observing at a wavelength of 1.3mm. VLBI allows the EHT to achieve an angular resolution of 20 micro-arcseconds — enough to read a newspaper in New York from a café in Paris [6].

    The telescopes contributing to this result were ALMA, APEX, the IRAM 30-meter telescope, the James Clerk Maxwell Telescope, the Large Millimeter Telescope Alfonso Serrano, the Submillimeter Array, the Submillimeter Telescope, and the South Pole Telescope [7]. Petabytes of raw data from the telescopes were combined by highly specialised supercomputers hosted by the Max Planck Institute for Radio Astronomy and MIT Haystack Observatory.

    Max Planck Institute for Radio Astronomy Bonn Germany

    MIT Haystack Observatory, Westford, Massachusetts, USA, Altitude 131 m (430 ft)

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    ESO/MPIfR APEX high on the Chajnantor plateau in Chile’s Atacama region, at an altitude of over 4,800 m (15,700 ft)

    IRAM 30m Radio telescope, on Pico Veleta in the Spanish Sierra Nevada,, Altitude 2,850 m (9,350 ft)

    East Asia Observatory James Clerk Maxwell telescope, Mauna Kea, Hawaii, USA,4,207 m (13,802 ft) above sea level

    The University of Massachusetts Amherst and Mexico’s Instituto Nacional de Astrofísica, Óptica y Electrónica
    Large Millimeter Telescope Alfonso Serrano, Mexico, at an altitude of 4850 meters on top of the Sierra Negra

    CfA Submillimeter Array Mauna Kea, Hawaii, USA, Altitude 4,080 m (13,390 ft)

    U Arizona Submillimeter Telescope located on Mt. Graham near Safford, Arizona, USA, Altitude 3,191 m (10,469 ft)

    South Pole Telescope SPTPOL. The SPT collaboration is made up of over a dozen (mostly North American) institutions, including the University of Chicago, the University of California, Berkeley, Case Western Reserve University, Harvard/Smithsonian Astrophysical Observatory, the University of Colorado Boulder, McGill University, The University of Illinois at Urbana-Champaign, University of California, Davis, Ludwig Maximilian University of Munich, Argonne National Laboratory, and the National Institute for Standards and Technology. It is funded by the National Science Foundation. Altitude 2.8 km (9,200 ft)

    European facilities and funding played a crucial role in this worldwide effort, with the participation of advanced European telescopes and the support from the European Research Council — particularly a €14 million grant for the BlackHoleCam project [8]. Support from ESO, IRAM and the Max Planck Society was also key. “This result builds on decades of European expertise in millimetre astronomy”, commented Karl Schuster, Director of IRAM and member of the EHT Board.

    The construction of the EHT and the observations announced today represent the culmination of decades of observational, technical, and theoretical work. This example of global teamwork required close collaboration by researchers from around the world. Thirteen partner institutions worked together to create the EHT, using both pre-existing infrastructure and support from a variety of agencies. Key funding was provided by the US National Science Foundation (NSF), the EU’s European Research Council (ERC), and funding agencies in East Asia.

    “ESO is delighted to have significantly contributed to this result through its European leadership and pivotal role in two of the EHT’s component telescopes, located in Chile — ALMA and APEX,” commented ESO Director General Xavier Barcons. “ALMA is the most sensitive facility in the EHT, and its 66 high-precision antennas were critical in making the EHT a success.”

    “We have achieved something presumed to be impossible just a generation ago,” concluded Doeleman. “Breakthroughs in technology, connections between the world’s best radio observatories, and innovative algorithms all came together to open an entirely new window on black holes and the event horizon.”
    Notes

    [1] The shadow of a black hole is the closest we can come to an image of the black hole itself, a completely dark object from which light cannot escape. The black hole’s boundary — the event horizon from which the EHT takes its name — is around 2.5 times smaller than the shadow it casts and measures just under 40 billion km across.

    [2] Supermassive black holes are relatively tiny astronomical objects — which has made them impossible to directly observe until now. As the size of a black hole’s event horizon is proportional to its mass, the more massive a black hole, the larger the shadow. Thanks to its enormous mass and relative proximity, M87’s black hole was predicted to be one of the largest viewable from Earth — making it a perfect target for the EHT.

    [3] Although the telescopes are not physically connected, they are able to synchronize their recorded data with atomic clocks — hydrogen masers — which precisely time their observations. These observations were collected at a wavelength of 1.3 mm during a 2017 global campaign. Each telescope of the EHT produced enormous amounts of data – roughly 350 terabytes per day – which was stored on high-performance helium-filled hard drives. These data were flown to highly specialised supercomputers — known as correlators — at the Max Planck Institute for Radio Astronomy and MIT Haystack Observatory to be combined. They were then painstakingly converted into an image using novel computational tools developed by the collaboration.

    [4] 100 years ago, two expeditions set out for Principe Island off the coast of Africa and Sobral in Brazil to observe the 1919 solar eclipse, with the goal of testing general relativity by seeing if starlight would be bent around the limb of the sun, as predicted by Einstein. In an echo of those observations, the EHT has sent team members to some of the world’s highest and most isolated radio facilities to once again test our understanding of gravity.

    [5] The East Asian Observatory (EAO) partner on the EHT project represents the participation of many regions in Asia, including China, Japan, Korea, Taiwan, Vietnam, Thailand, Malaysia, India and Indonesia.

    [6] Future EHT observations will see substantially increased sensitivity with the participation of the IRAM NOEMA Observatory, the Greenland Telescope and the Kitt Peak Telescope.

    [7] ALMA is a partnership of the European Southern Observatory (ESO; Europe, representing its member states), the U.S. National Science Foundation (NSF), and the National Institutes of Natural Sciences(NINS) of Japan, together with the National Research Council (Canada), the Ministry of Science and Technology (MOST; Taiwan), Academia Sinica Institute of Astronomy and Astrophysics (ASIAA; Taiwan), and Korea Astronomy and Space Science Institute (KASI; Republic of Korea), in cooperation with the Republic of Chile. APEX is operated by ESO, the 30-meter telescope is operated by IRAM (the IRAM Partner Organizations are MPG (Germany), CNRS (France) and IGN (Spain)), the James Clerk Maxwell Telescope is operated by the EAO, the Large Millimeter Telescope Alfonso Serrano is operated by INAOE and UMass, the Submillimeter Array is operated by SAO and ASIAA and the Submillimeter Telescope is operated by the Arizona Radio Observatory (ARO). The South Pole Telescope is operated by the University of Chicago with specialized EHT instrumentation provided by the University of Arizona.

    [8] BlackHoleCam is an EU-funded project to image, measure and understand astrophysical black holes. The main goal of BlackHoleCam and the Event Horizon Telescope (EHT) is to make the first ever images of the billion solar masses black hole in the nearby galaxy Messier 87 and of its smaller cousin, Sagittarius A*, the supermassive black hole at the centre of our Milky Way. This allows the determination of the deformation of spacetime caused by a black hole with extreme precision.

    More information

    This research was presented in a series of six papers published today in a special issue of The Astrophysical Journal Letters.

    The EHT collaboration involves more than 200 researchers from Africa, Asia, Europe, North and South America. The international collaboration is working to capture the most detailed black hole images ever by creating a virtual Earth-sized telescope. Supported by considerable international investment, the EHT links existing telescopes using novel systems — creating a fundamentally new instrument with the highest angular resolving power that has yet been achieved.

    The EHT consortium consists of 13 stakeholder institutes; the Academia Sinica Institute of Astronomy and Astrophysics, the University of Arizona, the University of Chicago, the East Asian Observatory, Goethe-Universitaet Frankfurt, Institut de Radioastronomie Millimétrique, Large Millimeter Telescope, Max Planck Institute for Radio Astronomy, MIT Haystack Observatory, National Astronomical Observatory of Japan, Perimeter Institute for Theoretical Physics, Radboud University and the Smithsonian Astrophysical Observatory.

    Links

    ESO EHT web page
    EHT Website & Press Release
    ESOBlog on the EHT Project

    Papers:

    Paper I: The Shadow of the Supermassive Black Hole
    Paper II: Array and Instrumentation
    Paper III: Data processing and Calibration
    Paper IV: Imaging the Central Supermassive Black Hole
    Paper V: Physical Origin of the Asymmetric Ring
    Paper VI: The Shadow and Mass of the Central Black Hole

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.


    Stem Education Coalition

    Visit ESO in Social Media-

    Facebook

    Twitter

    YouTube

    ESO Bloc Icon

    ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre EEuropean Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

     
  • richardmitnick 10:04 am on August 22, 2018 Permalink | Reply
    Tags: , , , , , , Messier 87,   

    From Instituto de Astrofísica de Canarias – IAC via Manu Garcia: “Discover the causes of the apparent displacement of a supermassive black hole” 


    From Manu Garcia, a friend from IAC.

    The universe around us.
    Astronomy, everything you wanted to know about our local universe and never dared to ask.

    IAC

    From Instituto de Astrofísica de Canarias – IAC

    Observing the core of Messier 87, HST-1 galaxy.

    1
    Messier 87 image with WFC3 HST (2016) with F814W filter. different knots are seen along the jet, including the first node HST-1. Credit: NASA/ESA Hubble.

    NASA/ESA Hubble Telescope

    NASA/ESA Hubble WFC3

    The study by two researchers from Instituto de Astrofísica reveals that the shift observed in the nucleus of the galaxy Messier 87 is not due to a shift of its massive black hole, but variations in light production in the center of the galaxy caused by bursts from a jet, a flow of material relativistic beam as the hole itself emits.

    Today it is assumed that all massive galaxies contain a supermassive black hole (SMBH, for its acronym in English) at its core. In recent years galaxies are looking for candidates to present a SMBHs displaced from its equilibrium position. Among the scenarios that can cause this displacement are merging two SMBHs or the existence of a binary system SMBHs, which gives information about galactic evolution and formation frequency and fusion of such objects.

    One of the galaxies candidates to present a displaced SMBHs is the giant elliptical Messier 87, containing one of the closest and best-studied active galaxy nuclei (AGN, for its acronym in English). Previous research SMBHs displacement of Messier 87 gave very different results, which was confusing. However, a new study by the student of the University of La Laguna (ULL), Elena López Navas has provided new data suggesting that the SMBHs of this galaxy is in its equilibrium position and shifts found must be variations in the production center or photocentric light caused by bursts from the relativistic jet, a flow of matter that the hole itself expelled outside at speeds near that of light.

    Research has been necessary to analyze a large number of high-resolution images of Messier 87 taken at different times and with different instruments installed on the Hubble Space Telescope (HST) and the Very Large Telescope (VLT).

    ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
    •KUEYEN (UT2; The Moon ),
    •MELIPAL (UT3; The Southern Cross ), and
    •YEPUN (UT4; Venus – as evening star).
    elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo

    “Given these results, we realized that the images showed a shift in the center of the galaxy were taken at a time when M87 was a huge explosion that could be measured in all ranges of the electromagnetic spectrum,” adds Almudena Prieto , co-author and researcher at the Institute of Astrophysics of the Canary Islands (IAC). This outbreak took place between 2003 and 2007 at the node nearest the nucleus known as Messier 87 HST-1 jet. During the duration of the phenomenon, this knot increased its flow coming to shine even more than the core itself. “Temporal analysis of displacement of center of the galaxy shows that indeed the burst is related to the change of the position of photocentric – clarifies the astrophysics, however, after this phenomenon, and the core photocentric meet occupying the same place, so we deduce that the core and the black hole are always in the same location coinciding with the minimum of galactic potential. ”

    2
    Displacements found (in milli – arcseconds) against the date of
    observation of each analyzed image. An increase of displacement is observed
    around 2005, when the maximum emission occurred in the first
    knot jet, HST-1. Credit: Elena Lopez.

    “In our work we have found that the SMBHs is in a stable over the last 20 years position; On the contrary, what changes is the production center of light or Fotocentro “says Lopez, author of this study, as work Master’s Research in Astrophysics, which has just been published in the journal <em>Monthly Notices of the Royal Astronomical Society</em> (MNRAS).

    The new data have caused great interest among the astrophysics community, as the study SMBHs position of M87 is crucial to understanding the evolution of this galaxy and analysis of other AGN jets. “In addition, this research reminds us that we must be cautious when considering variables sources with irregularities such as, in this case, a huge jet,” says Lopez, who is currently conducting a training grant in astrophysical research at the IAC.

    Work Master Thesis: E. Lopez Navas (2018 ULL), “Measurement and analysis of the displacement between the Fotocentro and the supermassive black hole in M87“.

    Contact:
    Elena Lopez Navas, ULL student / IAC: eln_ext@iac.es
    Almudena Prieto Escudero, a researcher at the IAC: aprieto@iac.es

    See the full article here.


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.


    Stem Education Coalition

    The Instituto de Astrofísica de Canarias(IAC) is an international research centre in Spain which comprises:

    The Instituto de Astrofísica, the headquarters, which is in La Laguna (Tenerife).
    The Centro de Astrofísica en La Palma (CALP)
    The Observatorio del Teide (OT), in Izaña (Tenerife).
    The Observatorio del Roque de los Muchachos (ORM), in Garafía (La Palma).

    Roque de los Muchachos Observatory is an astronomical observatory located in the municipality of Garafía on the island of La Palma in the Canary Islands, at an altitude of 2,396 m (7,861 ft)

    These centres, with all the facilities they bring together, make up the European Northern Observatory(ENO).

    The IAC is constituted administratively as a Public Consortium, created by statute in 1982, with involvement from the Spanish Government, the Government of the Canary Islands, the University of La Laguna and Spain’s Science Research Council (CSIC).

    The International Scientific Committee (CCI) manages participation in the observatories by institutions from other countries. A Time Allocation Committee (CAT) allocates the observing time reserved for Spain at the telescopes in the IAC’s observatories.

    The exceptional quality of the sky over the Canaries for astronomical observations is protected by law. The IAC’s Sky Quality Protection Office (OTPC) regulates the application of the law and its Sky Quality Group continuously monitors the parameters that define observing quality at the IAC Observatories.

    The IAC’s research programme includes astrophysical research and technological development projects.

    The IAC is also involved in researcher training, university teaching and outreachactivities.

    The IAC has devoted much energy to developing technology for the design and construction of a large 10.4 metre diameter telescope, the ( Gran Telescopio CANARIAS, GTC), which is sited at the Observatorio del Roque de los Muchachos.



    Gran Telescopio Canarias at the Roque de los Muchachos Observatory on the island of La Palma, in the Canaries, SpainGran Telescopio CANARIAS, GTC

     
  • richardmitnick 11:17 am on May 25, 2017 Permalink | Reply
    Tags: , , , , Messier 87, , Weird energy beam seems to travel five times the speed of light   

    From New Scientist: “Weird energy beam seems to travel five times the speed of light” 

    NewScientist

    New Scientist

    22 May 2017
    Joshua Sokol

    1
    Trick of the light. NASA and The Hubble Heritage Team (STScI/AURA)

    Please welcome to the stage a master illusionist. An energy beam that stabs out of galaxy Messier 87 like a toothpick in a cocktail olive is pulling off the ultimate magic trick: seeming to move faster than the speed of light [always means speed of light in a vacuum].

    Almost five times faster, in fact, as measured by the Hubble Space Telescope.

    NASA/ESA Hubble Telescope

    This feat was first observed in 1995 in galaxy Messier 87, and has been seen in many other galaxies since. It might have you questioning your entire reality. Nothing can break the cosmic speed limit, right? You can’t just flaunt the laws of physics… can you?

    If you want to just enjoy the illusion from your seat in the audience, stop reading. Otherwise, I welcome you backstage for a look at how the trick works – and how it’s helping astronomers to understand the fate of entire galaxies.

    Blobs faster than light?

    We’ve known about the jet of plasma shooting from the core of Messier 87 since 1918, when astronomer Heber Curtis saw a ray of light connected to the galaxy. To be visible from so far away, it had to be huge – about 6000 light years long.

    As modern astronomers now know, pretty much all galaxies have a central black hole that periodically draws in stars and gas clouds.

    Sag A* NASA Chandra X-Ray Observatory 23 July 2014, the supermassive black hole at the center of the Milky Way

    When gas begins to swirl down the drain, it heats up and magnetic fields focus some of it into jets of hot plasma. These jets shoot out at velocities near to – but not faster than – the speed of light.

    If you were to aim a telescope into the sky towards Messier 87, you would see that this lance of plasma is askew. Instead of pointing exactly into our line of sight, it’s angled a bit to the right.

    To understand the illusion, picture a single glowing blob of plasma starting at the base of this path and emitting a ray of light, both of which travel towards Earth. Now wait 10 years. In that time, the blob has moved closer at a sizeable fraction of the speed of light. That gives the rays emitted from that later position a few light years’ head start on the way to us.

    If you compare the first and second images from Earth’s perspective, it looks like the blob has just moved across the sky to the right. But because the second position is also closer to us, its light has had less far to travel than it appears. That means it seems to have arrived there faster than it actually did – as if the blob spent those 10 years travelling at ludicrous speed.

    One among many

    The jet from Messier 87 is more than just a curiosity, says Eileen Meyer at the University of Maryland, Baltimore County.

    All over the universe, outflows of energy from massive black holes can stop or start the formation of stars throughout galaxies. But it’s unclear how these outflows work and how much energy they contain.

    By appearing to move faster than light, jets such as the Messier 87 one change visibly over just a few years, which is unusual for distant objects like galaxies. That allows astronomers to make precise estimates of how fast the plasma is moving and thus how powerful the process is.

    Messier 87 is special because it is relatively close compared to other galaxies, making it easy to study. In 1999, astronomers used Hubble pictures of the jet taken over four years to see that plasma ripple outwards. In 2013, Meyer lengthened that to 13 years of images, which seemed to show that the plasma might also be moving in corkscrew-like spirals – as if it wasn’t complicated enough.

    Fresh results from Meyer, now being prepared for publication, extend that baseline again to a total of more than two decades and may offer new surprises. “Over 20 years, you know, things go bump in the night,” she says.

    And although the faster-than-light effect is old hat to her, she still stops to appreciate it sometimes. Most things we see travelling across the sky, such as planets and comets, are close to us. But Messier87 is tens of millions of light years away. “We can see, over a human lifetime, things moving,” she says. “Which is crazy.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: